The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/mips/mips/stack_machdep.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2005 Antoine Brodin
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __FBSDID("$FreeBSD$");
   31 
   32 #include <sys/types.h>
   33 #include <sys/systm.h>
   34 #include <sys/param.h>
   35 #include <sys/proc.h>
   36 #include <sys/stack.h>
   37 
   38 #include <machine/mips_opcode.h>
   39 
   40 #include <machine/pcb.h>
   41 #include <machine/regnum.h>
   42 
   43 static u_register_t
   44 stack_register_fetch(u_register_t sp, u_register_t stack_pos)
   45 {
   46         u_register_t * stack = 
   47             ((u_register_t *)(intptr_t)sp + (size_t)stack_pos/sizeof(u_register_t));
   48 
   49         return *stack;
   50 }
   51 
   52 static void
   53 stack_capture(struct stack *st, u_register_t pc, u_register_t sp)
   54 {
   55         u_register_t  ra = 0, i, stacksize;
   56         short ra_stack_pos = 0;
   57         InstFmt insn;
   58 
   59         stack_zero(st);
   60 
   61         for (;;) {
   62                 stacksize = 0;
   63                 if (pc <= (u_register_t)(intptr_t)btext)
   64                         break;
   65                 for (i = pc; i >= (u_register_t)(intptr_t)btext; i -= sizeof (insn)) {
   66                         bcopy((void *)(intptr_t)i, &insn, sizeof insn);
   67                         switch (insn.IType.op) {
   68                         case OP_ADDI:
   69                         case OP_ADDIU:
   70                         case OP_DADDI:
   71                         case OP_DADDIU:
   72                                 if (insn.IType.rs != SP || insn.IType.rt != SP)
   73                                         break;
   74                                 stacksize = -(short)insn.IType.imm;
   75                                 break;
   76 
   77                         case OP_SW:
   78                         case OP_SD:
   79                                 if (insn.IType.rs != SP || insn.IType.rt != RA)
   80                                         break;
   81                                 ra_stack_pos = (short)insn.IType.imm;
   82                                 break;
   83                         default:
   84                                 break;
   85                         }
   86 
   87                         if (stacksize)
   88                                 break;
   89                 }
   90 
   91                 if (stack_put(st, pc) == -1)
   92                         break;
   93 
   94                 for (i = pc; !ra; i += sizeof (insn)) {
   95                         bcopy((void *)(intptr_t)i, &insn, sizeof insn);
   96 
   97                         switch (insn.IType.op) {
   98                         case OP_SPECIAL:
   99                                 if (insn.RType.func == OP_JR) {
  100                                         if (ra >= (u_register_t)(intptr_t)btext)
  101                                                 break;
  102                                         if (insn.RType.rs != RA)
  103                                                 break;
  104                                         ra = stack_register_fetch(sp, 
  105                                             ra_stack_pos);
  106                                         if (!ra)
  107                                                 goto done;
  108                                         ra -= 8;
  109                                 }
  110                                 break;
  111                         default:
  112                                 break;
  113                         }
  114                         /* eret */
  115                         if (insn.word == 0x42000018)
  116                                 goto done;
  117                 }
  118 
  119                 if (pc == ra && stacksize == 0)
  120                         break;
  121 
  122                 sp += stacksize;
  123                 pc = ra;
  124                 ra = 0;
  125         }
  126 done:
  127         return;
  128 }
  129 
  130 void
  131 stack_save_td(struct stack *st, struct thread *td)
  132 {
  133         u_register_t pc, sp;
  134 
  135         if (TD_IS_SWAPPED(td))
  136                 panic("stack_save_td: swapped");
  137         if (TD_IS_RUNNING(td))
  138                 panic("stack_save_td: running");
  139 
  140         pc = td->td_pcb->pcb_regs.pc;
  141         sp = td->td_pcb->pcb_regs.sp;
  142         stack_capture(st, pc, sp);
  143 }
  144 
  145 int
  146 stack_save_td_running(struct stack *st, struct thread *td)
  147 {
  148 
  149         return (EOPNOTSUPP);
  150 }
  151 
  152 void
  153 stack_save(struct stack *st)
  154 {
  155         u_register_t pc, sp;
  156 
  157         if (curthread == NULL)
  158                 panic("stack_save: curthread == NULL");
  159 
  160         pc = curthread->td_pcb->pcb_regs.pc;
  161         sp = curthread->td_pcb->pcb_regs.sp;
  162         stack_capture(st, pc, sp);
  163 }

Cache object: 6245a03b1d00b7681799abb594c8ac33


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